Thermal-gravity fluid pumping method and apparatus

ABSTRACT

A large volume pumping method and apparatus comprising an economical thermal-gravity pumping system which is non-polluting, and employs relatively free and limitless, generally available, sources of energy input. The invention is particularly useful in pumping water into a tank reservoir for the ultimate purpose of generating hydroelectric power by conventional turbine-operated generator.

United States Patent [191 METHOD AND APPARATUS Ledner Feb. 5, 1974 [54]THERMAL-GRAVITY FLUID PUMPING 2,241,020 5/1941 Shoeld 60/25 2,212,2818/1940 Ullstrand 60/25 x [76] Inventor: Albert C. Ledner, 5328 BellaireDr.,

New Orleans, La 70124 Primary ExaminerCarlton R. Croyle AssistantExaminer-Richard Sher 2 F d: N 2 197 2] 116 (W 2 Attorney, Agent, orFirmJ. Gibson Semmes [21] Appl. No.: 309,972

Related US. Application Data 1 [63] Continuation-impart of Ser. No.249,032, May 1, [57] ABSTRACT A large volume pumping method andapparatus com- [52] US. Cl 417/53, 60/25, 417/379, prisi g an conomicalthgrmabgravity pumping ystem 417/389 which is non-polluting, and employsrelatively free and Ill. Cl. limitless generally available ources ofenergy input Fleld of Search 55, 379, The invention is particularlyuseful in pumping water 1 60/25 into a tank reservoir for the ultimatepurpose of generating hydroelectric power by conventional turbine- [56]References Cited Operated generaton UNITED STATES PATENTS 3,604,8229/1971 Saxe 60/25 X. 5 Claims, 10 Drawing Figures PAIENIEB HOT WATER INHOT WA RETU 310 snasnnra' PATENTED I 3.790.305

sum 2 or 3 I TO TURBINE/GENERATOR 4 TANKRESERVOIR FROM TAIL WATER POOLRESERVOIR r VALVE SWITCH LEGEND.

O VALVE CLOSED O VALVE OPEN A ACTIVATING SWITCH ENERGIZING SWITCHINDICATED (E) AND DE-ENERGIZING ACTIVATING SWITCH INDICATED (A) V EENERGIZED SWITCH' X DE ENERGlZED SWITCH FIGSc FIGBd FIGSeTHERMAL-GRAVITY FLUID PUMPING METHOD AND APPARATUS REFERENCE TO RELATEDAPPLICATIONS tled THERMAL-GRAVITY FLUID PUMPING METHOD AND APPARATUS, inthe name of the same inventor.

BACKGROUND OF THE INVENTION The use of natural sources of energy as inheliothermal systems viz: solar-energy utilization and those using heatenergy of the sea in which thermodynamic agents are used have beenadvanced in varying degrees of application, relative to producingelectrical power. None of these systems has proven entirely satisfactoryor commercially feasible because of low conversion efficiency,intermittent operations, high costs, and highly restrictive conditionsfor plant locations. Of the known art, reference is made to Santos US.Pat. No. 2,660,030 and Patterson Pat. No. 2,884,866, respectivelydistinguishable from the present invention.

SUMMARY OF THE INVENTION The present invention provides method and meansfor pumping large volumes of water discharged from turbines, operatingelectric generators, into verticaltank reservoirs for recirculationthrough said turbines. In the practice of the invention conversionefficiency is relatively high; operation, continuous; and plant cost,comparatively low. Maintenance and operational costs and restrictiveconditionsfor plant locations are moderately low. The invention residesin-the application'of thermal and gravity forces in a selected andcontrolled working relationship to produce continuous fluid pumping. Inessence, the invention embodies the use of a hydraulic-type pump havinga thermodynamic fluid such as fluoro-chloro hydrocarbon functioning as aliquid piston, acting upon water. The invention provides a continuouscycle of reciprocating flow of water, resulting from the controlledexpansion and contraction of the thermodynamic agent by means ofseparate heat exchangers, which may conduct coldwater on the contractioncycle and hot water on the expansion cycle. Specific preconditionspermit use of a natural, free source of unrecirculated cooling waterthrough its heat exchanger and a minimum Btu heat input for therecirculated hot water through its heat exchanger. Essentially, theinvention method comprises practical utilization of heat as an energysource, converting said heat into work and secondarily provides aneconomical, pollution-free system, using a relatively limitless sourceof convertible energy for pumping water into tank reservoirs for use ingenerating hydroelectric power by conventional turbine-operatedgenerators.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation ofa preferred means of practicing invention, the exterior portions of theoperating tanks being exposed to the interiors thereof;

FIG. 2 is a top plan view of the FIG. 1 concept;

FIG. 3 isa horizontal sectional view on the line 3-3 of FIG. 1, showingthe relationship of two tanks, one within the other;

FIG. 4 is a horizontal sectional view on the line 4-4 I of FIG. 1,showing a series of condensing tubes within the condensing tank;

FIGS. 5A through 5E are schematic views of two tanks of the fourthermal-gravity operating tanks showing the relative positions of thethermodynamic fluid and water at maximum, and mid points of expansionand contraction'cycles representing the sequence of operation throughone full pumping cycle; and

FIG. 6 is a valve and 'switch scheduling chart indicating theinterrelated operational sequence of the controlling valves and switchesfor the thermal-gravity pump, representing the sequence of operationthrough one full pumping cycle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the selected embodiment ofthe invention, there is illustrated in FIGS. 1 and 2, a Thermal-Gravitypumping system comprising four cylindrical tanks, 100, 200, 300 and 400.Tank unit 200 is disposed directly below tank unit with connectingpiping 214 and 216. Tank unit 300 is disposed directly below tank unit200 with connecting piping 314 and 316. Tank unit 400 is disposedadjacent to tank 200 with connecting piping 412. Solenoid operated valve224, on piping 214, controls the flow of thermodynamic vapor from tank200 into tank 100. Check valve 226, on piping 216, controls the returnflow, by gravity, of a thermodynamic fluid 340 condensate from tank 100into tank 210 which is housed within tank 200. Solenoid operated valve324, on piping 314, controls the flow of thermodynamic vapor from tank300 into tank 200. Check valve 326, on piping 316 controls the returnflow, by gravity, of a thermodynamic fluid 340 condensate from tank 210into tank 300.

Construction and detailing of Tanks 100, 200, 300, and 400 are ofconventional type as applies to pressurized tanks. The tanks aresupported by suitable structural members 150, which in turn aresupported on concrete Foundation 500.

Tank Unit 100 functions.as the condenser unit i.e., contraction side ofthe system and consists of two separate chambers, being the upperchamber and 110 being the lower chamber. Within the upper chamber 1 10are heat exchanger tubes consisting of a series of vertical tubes, eachtube sealed at its top and open at its bottom where said tube seats intoplate which separates and seals chamber 110 from 110'. Piping 112 attop.of unit 100 supplies cold water to the upper chamber 110 of unit 100which circulates around all the condensing tubes 130, as illustrated inFIGS. 1 and 4, during its flow through chamber 110 to piping 114 whichis the conduit for said cold water from chamber 1 10 to a heat exchangerconsisting of a continuous coil of suitable metal tubing 120, asillustrated in FIG. 1, being of conventional design and fabrication andhoused in the lower portion 113 of chamber 110 of unit 100. Return coldwater piping 116, FIG. 1, connects to the discharge end of metal coilheat exchanger 120. Plate 160 with collared opening 180, as illustratedin FIG. 1, separates chamber 110 into an upper portion 111 and lowerportion 113. Collared opening I80 provides a common vapor pressureenvironment within the two portions of chamber 110 at all times.

Tank unit 300 functions as the boiler unit; i.e., expansion side of thesystem. Within tank unit 300 is a heat exchanger consisting of acontinuous coil of suitable metal tubing 320, as illustrated in FIG. 1,being of conventional design and fabrication. Piping 312 and 310 at topof unit 300 are supply and return hot water piping, as illustrated inFIG. 1, to and from metalcoil heat exchanger 320.

Tank unit 200 functions as the interchange unit between tanks 1'00 and300, receiving thermodynamic vapor 350 from tank 300 during an expansionphase prior to'said vapor flow into tank 100 during a contraction phaseand also receives a thermodynamic fluid 340 condensate from tank 100during a contraction phase prior to said condensate flow into tank 300during an expansion phase. Tank unit 200 also serves as the containerfor the liquid piston of thermodynamic fluid 340 which is retainedbetween the two tanks 200 and 210 as illustrated in FIGS. 1 and 3.

Piping 214 at top of tank 200, as illustrated in FIG. 1, serves asconduit for the flow of thermodynamic vapor 350 into the lower portion 113 of chamber 110 of tank unit 100 during a contraction phase. Saidpiping 214 connects to an air cooled heat exchanger consisting of acontinuous coil of suitable metal tubing 140, as illustrated in FIG. 1,being of conventional design and fabrication. Said air cooled heatexchanger coil 140 connects to the vapor discharge unit 145 housedwithin the lower portion 113 of chamber 110"of tank unit 100, positioneddirectly below plate 160 as illustrated in FIG. 1. Vapor discharge unit145 is fabricated from suitable metal tubing, formed in a circularpattern with a series of equally spaced small discharge nozzles 146located on the top side of said discharge unit so that vapor isdischarged against the bottom side of plate 160.

Tank unit 400 functions as a subsidiary tank of tank unit 200, servingas the container for water 440 which is pumped in and out of tank 400through piping 420 and 418 respectively, as illustrated in FIG. 1. Theliquid piston of thermodynamic fluid 340 flowing to and from tank unit200 flows through piping 412 into tank 400, acting upon the water 440 asillustrated in FIGS. A through 5E. Tank 400 is connected to a tankreservoir with related turbine/generator unit and tail water poolreservoir, not shown, by piping 418 and 420, respectively, asillustrated in FIGS. 1 and 2. Check valves 426 and 426' on piping 418and 420, respectively, provide control of the one way flow of water fromtank 400 to a tank reservoir with related turbine/generator unit, notshown, and from a tail water pool reservoir, not shown, to tank 400.

Obvious calculations are required for determining the cubic amount andspecific fluoro-chloro hydrocarbon, known as Freon or Genetron, used infilling the system, as well as method employed installing the requiredamounts of said material as illustrated in FIGS. 1 and 5A through 5E.For simplicity, all conventional valves, pressure gauges, temperaturereading instruments and other types of recording instruments andinsulation material have been omitted from the drawings; suffice it tosay that the operative function of the apparatus will be clear from theensuing details.

FIGS. 5A through 5E are schematic views of tanks 200 and 400 showing theinterrelated positions of the thermodynamic fluid 340 and vapor 350 andwater 440 at the maximum and mid points of the contraction and expansioncycles, representing the sequence of operation through one full pumpingcycle for one thermaL gravity pump unit. Electrically energized mercuryfloat switches 270 and 280 within tank unit 200 control the operation ofthe solenoid valves 224 and 324 serving tanks 200 and 300, respectively.The sequenced control and operation of the solenoid valves and mercuryfloat switches are indicated on the valve and switch scheduling chart,FIG. 6. I

The thermal-gravity pumping system operates as follows:

Beginning at the start of an expansion cycle, tanks 200 and 400, FIG.5A, two pre-conditions exist: 1 hot water continuously circulated, froma source not shown, through the heat exchanger coil 320, in tank 300,has caused the thermodynamic fluid to boil, resulting in the expansionof vapor, raising the pressure in' the boiler tank 300 to an amountwhich, at all times during operation, would be a pre-determined amountmore than the working head pressure of the water in the tank reservoirrequired for the turbine operation; 2) cold water continuouslycirculated, from a source not shown, around heat exchanger tubes 130 andthrough heat exchanger coil 120 in condensing tank unit has cooled thethermodynamic vapor 350 in chamber of tank unit 100, causing thethermodynamic vapor 350 to condense, thus lowering the pressure in thecondenser chamber 110 of tank unit 100 to an amount which, at all timesduring operation, would be a pre-determined amount less than the headpressure of the tail water pool reservoir at atmospheric pressure. Atthe start of an expansion cycle, tank 200, FIG. 5A, the thermodynamicfluid 340 liquid piston has just completedits upward movementterminating a contraction cycle and thus, activating switch 270 which,at this point of operation, closes and opens respectively the indicatedsolenoid valves 324 and 224, energizes switch 280 and de-energizesitself, all in accordance with the sequence indicated on the valve/-switch chart, FIG. 6. Solenoid valve 224 is closed and solenoid valve324 is opened, causing the thermodynamic liquid piston 340, tank 200, tomove downward under pressure of the expanding thermodynamic vapor 350released from tank 300 through piping 314.

Through hydraulic action, piston 340 reacts instanta neously on thewater 440 in tank 400, thus pumping water into the tank reservoir, notshown. During this phase of the pumping cycle thermodynamic fluid 342condensate which has been retained within the condensate reservoir atthe bottom of tank 210, resulting from" the previous contraction cycleduring which thermodynamic fluid condensate flowed into tank 210 fromtank unit 100, is allowed to flow into tank 300. This return flow, bygravity, of the thermodynamic fluid 342 condensate back into boiler tank300 is possible due to the fact that the pressure in tanks 200, 210 and300 during an expansion cycle-is the same. Check valve 326 on piping 316allows one-way flow only, from tank 210 into tank 300 so that during acontraction phase no flow of thermodynamic fluid 342 from tank 300through piping 316 occurs.

At the start of a contraction cycle, tank 200, FIG. 5C, thethermodynamic fluid 340 liquid piston has just completed its downwardmovement terminating an expansion cycle and thus, activating switch 280which, at

this point of operation, opens and closes the indicated solenoid valves224 and 32 4, energizes switch 270 and de-energizes itself, all inaccordance with the sequence indicated on the valve/switch chart, FIG.6. Solenoid valve 324 is closed and solenoid valve 224 is opened,causing the thermodynamic liquid piston 340, tank 200, to move upwardresulting from the immediate release of thermodynamic vapor 350 intochamber 110 of tank unit 100, flowing from tank 200 through piping 214into air cooled heat exchanger coil 140 and then into vapor dischargeunit 145 as illustrated in FIG. 1.

The upward movement of thermodynamic liquid piston 340 reactsinstantaneously on the water 440 in tank 400 through hydraulic action,thus pumping water from the tail water pool reservoir, not shown, intotank 400. This reverse flow of water into tank 400 is possible due tothe fact that the thermodynamic vapor pressure in chamber 110 is belowatmospheric pressure and also less than the head pressure of the tailwater poolreservo1r.

The air cooled heat exchanger coil 140 functions as a first phasecondensing unit, providing immediate reduction in vapor pressure priorto its discharge into the second phase condensing area, being thatportion of chamber 110 below plate 160. A mixture of thermodynamic fluidcondensate and vapor is released through vapor discharge unit 145, vianozzles 146, said mixture discharged being against the underside ofplate 160 as illustrated in FIG. 1. Since the top side of plate 160retains a certain amount of thermodynamic fluid condensate 344', due tothe extension of collar 180 above the opening in plate 160, there occursan additional heat exchange when said fluid and vapor discharged fromvapor discharge unit 145 hits the underside of plate 160. In this heatexchange a certain portion of discharged vapor is condensed whichcollects at the bottom-of chamber 110 as thermodynamicfluid 346'condensate.

The discharged vapor 350 which is not condensed flows around heatexchanger coil 120 resulting in further condensation during its finalflow into the third phase condensing unit, being that portion of chamber110' above plate 160, including flow into heat exchanger tubes 130.Thermodynamic fluid 344' condensate resulting from condensation withincondensing tubes 130 collects in the condensate reservoir formed byplate-l60 and collar 180. The overflow condensate 340 which flowsthrough collared opening 180 to the bottom of chamber 110 is allowed toflow into tank 210. This return flow, by gravity, of said condensatethrough piping 216 is possible due to the fact that the pressure intanks 200, 210 and chamber 110 of tank unit 100 during the latterportion of a contraction cycle is the same. Check valve 226 on piping216 allows oneway flow only, from chamber 110 into tank 210 so thatduring an expansion phase no flow of thermodynamic fluid 340' condensateor vapor 350 from tank 210 through piping 216 occurs.

At the completion of a contraction cycle, tank 200, FIG. 5E, thethermodynamic fluid 340 liquid piston has completed its upward movement,thus activating switch 270, resulting in the immediate start of a newexpansion-contraction cycle. It becomes obvious from the abovedisclosure that with two or more thermal-gravity pump units a continuouspumping operation of water, to and from a tank reservoir with relatedturbine/generator unit and tail water pool reservoir, is possible.

The present invention offers the means of producing power, primarily forconversion to electrical energy, at a relatively lower cost than hasbeen possible in the past, with the additional features of beingnon-polluting and using a relatively free and limitless source of energyinput.

Another important feature of the present invention resides in the use ofanatural, free source of unrecirculated cooling water through heatexchanger coil unit for the condenser unit. Any suitable cold watersource such as streams, rivers, lakes, seas, etc. with maximumtemperature of approximately F. may be used. The minimum constanttemperature of the water to be used in the condenser unit coil is animportant criterion in determining the specific fluoro-chlorohydrocarbon used in the pumping system.

Another important feature of the present invention resides in the use ofa free or relatively inexpensive source of hot water for use throughheat exchanger coil unit for the boiler unit. The natural free sourceswould include Solar-energy, heliothermalapplication in areas permitting,geothermal heat sources in areas permitting, and biothermal process suchas compost system for municipal garbage disposal, as well as combustionheat from conventional municipal or industrial incineration plants.Other sources which may be free or relatively inexpensive would includewaste heat from many diversetypes of industrial processes, including thetremendous waste heat from existing atomic energy generating plantswhich presently pose a serious thermal pollution problem.

Another important feature of the present invention resides in theeconomic use of Btu heat input for the boiler unit. For example, it hasbeen observed that with 170 F. supply water, circulated through the heatexchanger coil unit for the boiler unit, the average temperature of thereturn water is F. during the expansion cycle. Obviously, this indicatesthat, once the hot water source is at the necessary temperature for arequired vapor pressure during the expansion cycle, the Btu input forthehot water return from the heat exchanger coil unit will be minimalcompared with existing heat conversion systems. This feature is of greatimportance when the present pumping system requires recirculation of thehot water due to the unavailability of natural or man-made waste heatsources.

Another important feature of the present invention resides in the use ofwater in working relationship with the thermodynamic fluid. Thethermodynamic fluid functions as a liquid piston, providing a relativelylow friction hydraulic system compared to a mechanical system. Also, thethermodynamic fluid provides its own seal in maintaining a closed systemfor the thermodynamic vapor.

I claim:

1. A method for pumping water employing enclosed thermodynamic pumpingliquids in expansion and contraction relation to the water to effectreciprocating movement of said thermodynamic liquid relative to thewater, comprising the steps of:

A. disposing in expansion cycle a first volume of thermodynamic liquidin a first closure;

B. disposing a second volume of the thermodynamic liquid in a secondclosure which is connected to the said first closure;

C. introducing a volume of water to be pumped into a third closure whichis connected to the said second closure;

D. heating the volume of thermodynamic liquid within the said firstclosure to vaporize a portion of the thermodynamic liquid andtransferring the created thermodynamic vapor to the said second closure,thereby increasing the pressure within the second closure;

E. channelling the thermodynamic liquid of the second closure away andupwardly from the second closure to the third closure in response to therise in pressure within said second closure, for respon' sive movementthereof in contact with the water in the third closure, whereby thevolume of water in the third closure is by hydraulic action of thethermodynamic liquid therein exhausted from the third closure as thethermodynamic liquid enters in response to the pressure of thethermodynamic vapor within said second closure;

F. blocking the transfer of heated thermodynamic vapor from the firstclosure to the second closure;

G. directing the said thermodynamic vapor from the second closure to afourth closure thereby lowering the pressure within the second closure;

H. condensing the thermodynamic vapor in the fourth closure forsubsequent return of the condensate to the second closure incommencement of a contraction cycle;

. chanelling the thermodynamic liquid from the third closure back to thesecond closure in response to the reduction in pressure therein;

1. drawing water into the third closure in response to the negativepressure therein;

K. returning a portion of thermodynamic liquid from the second closureto the first; and

L. repeating Steps C through K whereby water is continuously pumped fromthe third closure in response to the respective expansion andcontraction cycles.

2. The method according to claim 1 wherein the thermodynamic liquidcomprises a fluid from the group consisting of fluoro-chlorohydrocarbons.

3. An apparatus for pumping water comrising: A. first, second, third,and fourth enclosed tanks; B. a volume of thermodynamic liquid containedin at least a part of the first and second of said tanks; C. means forheating the thermodynamic liquid in said first tank, whereby a vaporthereof is generated;

D. conduit means for conveying said vapor from said first tank to saidsecond tank;

E. conduit means connecting said second tank to said third tank, wherebythe thermodynamic liquid in said second tank may be forced from saidsecond tank to said third tank by the pressure of the vapor generated insaid first tank;

F. means for conveying water to and from said third tank; whereby watermay be forced out of said third tank by the introduction ofthermodynamic liquid from said second tank,.and whereby water may bedrawn into said third tank upon the transfer of thermodynamic liquidfrom the third tank back to said second tank;

G. conduit means connecting said second tank to said fourth tank,whereby said vapor may be conveyed to said fourth tank;

H. means for cooling the vapor in said fourth tank for returning saidvapor back into liquid state;

I. conduit means for returning thennodynamic liquid from said fourthtank to said first tank;

J. means for automatically controlling the cyclic admission of vaporfrom the first tank to the second tank and from the second tank to thefourth tank so that cyclic pumping of water into and out of said thirdtank is accomplished.

4. The apparatus of claim 3 wherein the thermodynamic liquid is selectedfrom the group consisting of fluoro-chloro hydrocarbons.

5. The apparatus according to claim 3 further comprising:

means for producing signals in response to predetermined low and highlevels of the thermodynamic liquid in the second tank, respectively;

said means for controlling the cyclic admission of the vapor comprisingvalve means in said conduit connecting said first tank to said secondtank for opening in response to said high level signal and closing inresponse to said low level signal;

said means for cooling the vapor comprising valve means in said conduitmeans connecting said second tank to said fourth tank for closing inresponse to said high level signal and opening in response to said lowlevel signal; 1

means for collecting the vapor condensate comprising check valve meansfor permitting one-way flow from the fourth tank to the first tank.

1. A method for pumping water employing enclosed thermodynamic pumpingliquids in expansion and contraction relation to the water to effectreciprocating movement of said thermodynamic liquid relative to thewater, comprising the steps of: A. disposing in expansion cycle a firstvolume of thermodynamic liquid in a first closure; B. disposing a secondvolume of the thermodynamic liquid in a second closure which isconnected to the said first closure; C. introducing a volume of water tobe pumped into a third closure which is connected to the said secondclosure; D. heating the volume of thermodynamic liquid within the saidfirst closure to vaporize a portion of the thermodynamic liquid andtransferring the created thermodynamic vapor to the said second closure,thereby increasing the pressure within the second closure; E.channelling the thermodynamic liquid of the second closure away andupwardly from the second closure to the third closure in response to therise in pressure within said second closure, for responsive movementthereof in contact with the water in the third closure, whereby thevolume of water in the third closure is by hydraulic action of thethermodynamic liquid therein exhausted from the third closure as thethermodynamic liquid enters in response to the pressure of thethermodynamic vapor within said second closure; F. blocking the transferof heated thermodynamic vapor from the first closure to the secondclosure; G. directing the said thermodynamic vapor from the secondclosure to a fourth closure thereby lowering the pressure within thesecond closure; H. condensing the thermodynamic vapor in the fourthclosure for subsequent return of the condensate to the second closure incommencement of a contraction cycle; I. chanelling the thermodynamicliquid from the third closure back to the second closure in response tothe reduction in pressure therein; J. drawing water into the thirdclosure in response to the negative pressure therein; K. returning aportion of thermodynamic liquid from the second closure to the first;and L. repeating Steps C through K whereby water is continuously pumpedfrom the third closure in response to the respective expansion andcontraction cycles.
 2. The method according to claim 1 wherein thethermodynamic liquid comprises a fluid from the group consisting offluoro-chloro hydrocarbons.
 3. An apparatus for pumping water comrising:A. first, second, third, and fourth enclosed tanks; B. a volume ofthermodynamic liquid contained in at least a part of the first andsecond of said tanks; C. means for heating the thermodynamic liquid insaid first tank, whereby a vapor thereof is generated; D. conduit meansfor conveying said vapor from said first tank to said second tank; E.conduit means connecting said second tank to said third tank, wherebythe thermodynamic liquid in said second tank may be forced from saidsecond tank to said third tank by the pressure of the vapor generated insaid first tank; F. means for conveying water to and from said thirdtank; whereby water may be forced out of said third tank by theintroduction of thermodynamic liquid from said second tank, and wherebywater may be drawn into said third tank upon the transfer ofthermodynamic liquid from the third tank back to said second tank; G.conduit means connecting said second tank to said fourth tank, wherebysaid vapor may be conveyed to said fourth tank; H. Means for cooling thevapor in said fourth tank for returning said vapor back into liquidstate; I. conduit means for returning thermodynamic liquid from saidfourth tank to said first tank; J. means for automatically controllingthe cyclic admission of vapor from the first tank to the second tank andfrom the second tank to the fourth tank so that cyclic pumping of waterinto and out of said third tank is accomplished.
 4. The apparatus ofclaim 3 wherein the thermodynamic liquid is selected from the groupconsisting of fluoro-chloro hydrocarbons.
 5. The apparatus according toclaim 3 further comprising: means for producing signals in response topredetermined low and high levels of the thermodynamic liquid in thesecond tank, respectively; said means for controlling the cyclicadmission of the vapor comprising valve means in said conduit connectingsaid first tank to said second tank for opening in response to said highlevel signal and closing in response to said low level signal; saidmeans for cooling the vapor comprising valve means in said conduit meansconnecting said second tank to said fourth tank for closing in responseto said high level signal and opening in response to said low levelsignal; means for collecting the vapor condensate comprising check valvemeans for permitting one-way flow from the fourth tank to the firsttank.